I don’t have to tell you how magical this place is. like no other places I’ve ever been before anywhere in the world. Any campground in the park would be okay. I planned to try different camps but ended up staying at Avalanche the whole time. Come early but not 5am/6am early like some of the posts suggest. +/-8am is the sweet spot because that’s typically when people leave, just drive into the campground and see if there’s an empty place, park there or let someone hold on to it, then go to the self check-in board to get the tag, write the info, drop the money, and bring the other half of the tag back to mount at your camp. That’s all. I was there the July 4 week, it was busy but I can see a good number of people in and out every day so don’t be too worried about not getting a place. Last resort, you can go to the private campgrounds just right outside the gates, they’re always available, and try again next day. Also if you’re gonna hike, i would definitely suggest that you go out very early. I leave my camp around 6am or 7am latest and often have the entire road (to the sun) for myself, plus chances are you will see animals and parking lots are still empty (likely filled by 9am).